Paper folding endurance
Paper folding endurance refers to the ability of paper to withstand folding. It is the logarithm of the number of reciprocating 180° folds that paper can withstand under a certain pressure. The domestic custom is expressed by the number of times of reciprocating folding, that is, the number of times the paper is reciprocally folded 180° until it is broken.
The transverse and longitudinal tensile strengths of paper are different, so the folding endurance is also different, which are called transverse folding endurance and longitudinal folding endurance respectively. Generally, the longitudinal folding endurance is larger than the transverse folding endurance.
Folding endurance has no direct impact on printability, but has an impact on post-processing suitability of printed products. In addition, some printed materials that are used in daily life have requirements for paper folding endurance, such as banknotes, securities, book covers, maps, charts, etc., which are often folded backwards during use, requiring high folding endurance.
Paper tearing is a technical index for evaluating the shear resistance of paper. The force, in mN, required to tear pre-slit paper to a given length.
Paper Tear
The tearing degree of paper is different in the horizontal direction and the vertical direction. Generally, the vertical direction is easier to tear than the horizontal direction.
Paper tearing is an important indicator of mechanical strength for web printing.
